Lamar Odom’s drug dealers could be linked to the $250,000 jewelry heist at Lamar and Khloe’s house … because we’re told the dealers threatened to break in to get the money Lamar never paid.

We’re told Lamar was getting text messages threatening his safety and also warning him they would break into his home to get even.

Cops don’t know who stole the expensive jewelry but we’re told there was no sign of forced entry. One source says he has reason to believe one of the dealers had connections to someone who works for the family and had lawful access to the house.

Odom no longer lives in the home and Khloe has put the mansion up for sale.